Static Folders

Static folder ingress rules serve files directly from a folder in the virtual filesystem — no script execution required. Use this for HTML pages, CSS, images, JavaScript bundles, and other static assets.

How It Works

1. An ingress rule with type STATIC_FOLDER maps a URL prefix to a folder in the virtual filesystem
2. When a request arrives, the engine resolves the relative path after the route prefix
3. It walks the virtual filesystem tree to find the matching file
4. The file is served with a Content-Type guessed from the filename
5. Directory requests serve index.html automatically

Key Differences from Script Ingress

Aspect	HTTP Ingress	Static Folder
scriptUUID points to	A script file	A folder tree item
Execution	Script runs per request	No script — file served directly
Content-Type	Set by Results chain	Auto-detected from filename
Index behavior	N/A	Serves index.html for directory URLs

Route Mapping

Given a static folder ingress with route /site pointing to a folder containing:

/my-website/
  index.html
  styles.css
  app.js
  images/
    logo.png

The following URLs are served:

URL	File served
/backend/site	index.html
/backend/site/	index.html
/backend/site/styles.css	styles.css
/backend/site/app.js	app.js
/backend/site/images/logo.png	images/logo.png

The /http_root Route

The special route /http_root maps to the web server root (/). This is useful for serving a full website at the root URL:

Ingress: STATIC_FOLDER, route = /http_root
Folder:  /public-website/

/public-website/index.html  →  http://your-host/
/public-website/about.html  →  http://your-host/about.html
/public-website/css/main.css → http://your-host/css/main.css

Content-Type Detection

Content types are guessed from the file extension using Java's URLConnection.guessContentTypeFromName(). Common mappings:

Extension	Content-Type
.html	text/html
.css	text/css
.js	application/javascript
.json	application/json
.png	image/png
.jpg / .jpeg	image/jpeg
.svg	image/svg+xml
.pdf	application/pdf
.txt	text/plain

Use Cases

Single-Page Application

Serve a built SPA (React, Vue, etc.) by pointing a static folder at the build output:

/spa-app/
  index.html
  assets/
    main.js
    style.css

Marketing Site

Serve a static marketing site alongside your API endpoints:

Static folder ingress: /http_root → /marketing-site/
HTTP GET ingress:      /api/contact → /ingresses/api/contact-form.js

Documentation

Host generated documentation (e.g., from a static site generator):

Static folder ingress: /docs → /documentation/

TIP

Static folders are the simplest way to serve frontend assets. They require no JavaScript handler code and are served directly from the virtual filesystem.